We specialise in difficult sites, on both natural and filled ground, where ground improvement can be an alternative to deep footings. Black Geotechnical has formed a working relationship with Landpac Technologies Pty Ltd, who provide a high energy impact compaction service to the construction industry.
High energy impact compaction is a rapid controlled form of dynamic compaction that provides in-situ improvement to mixed fill, landfills and low strength natural soil, to allow development to proceed on high level footings, rather than on more expense deep footings.
Black Geotechnical's role is to conduct geotechnical investigations, or to review geotechnical investigations by others, to assess suitability of high energy impact compaction. If Landpac proceeds with high energy impact compaction, Black Geotechnical provides geotechnical engineering supervision and post compaction testing. Finally, Black Geotechnical provides certification that the improved site will satisfactorily support the proposed development.
Black Geotechnical are also involved with other forms of ground improvement including dynamic compaction, high energy impact compaction, rapid impact compaction, lime/cement stabilisation and removal and replacement. In China, we have been involved with vacuum preloading and soil/cement piles.
Some of Black Geotechnical's experience with ground improvement includes:
Black Geotechnical and Landpac have successfully completed about 100 projects where the in-situ compaction of up to 4m of un-engineered fill has allowed development to proceed on high level footings in fill. In some cases the projects involve un-engineered fill over weak compressible alluvial soil. These projects include:
- Bunnings Stores at Epping and Scoresby.
- Three hectare Direct Factory Outlet at Brisbane Airport (fill over weak alluvium)
- Two hectare supermarket and specialty shop development at Leopold
- Police station at Croydon (Vic) on an old service station site with areas of unegineered fill up to 3m deep adjacent to natural soil
- One hectare residential subdivision at Wantirna
- Two hectare residential subdivision at Merrylands
- 4.25 hectare residential development at Varsity Lakes (fill over weak clay and loose sand, ground improvement included soil wicks and preloading)
- 5.5 hectare factory/warehouse development at Chullora
- Four hectare industrial subdivision at Riverwood
- Three hectare factory/warehouse development at Brisbane Airport (fill over weak alluvium)
- One hectare factory/warehouse development at Braeside
- 4.4 hectare container terminal at Altona (pavement only)
- 0.5 hectare switchyard at Cairns
Black Geotechnical and Landpac have successfully completed a number of projects where development has proceeded on landfill, including putrescible waste. Some of these projects are listed below.
- 30 hectare site at Runaway Bay on 2m of refuse with a shallow capping, which has been developed as a sports centre including a championship athletics tracks, gymnasium, Olympic pool building and double story residential units.
- Bunnings store at Shepparton on 4m of refuse. The building columns are supported by high level footings placed on 4m x 4m excavations through the fill that were backfilled with sand and compacted by high energy impact compaction. The floor slab and heavy duty pavements are supported on the high energy impact compacted refuse.
- Ceres Environmental Park, Brunswick. New 1000m2 reception centre on high energy impact compacted landfill that is up to 20m deep in an old bluestone quarry. A two level office, a large hall and a community space building are proposed above the landfill after high energy impact compaction combined with MASW testing to define the quarry edge.
- Two hectare site in Pudong (Shanghai) with 2-3m of uncontrolled fill including refuse over 20m of soft to firm 'pudong mud' developed as a factory and two storey office for Parker Hanifan. The office and factory are supported on high level strip and pad footings on sand 'columns' through fill constructed in a similar manner to that adopted for the Shepparton Bunnings store.
- Taren Point. Five hectare site developed as a retirement village on up to 3.5m of refuse. High energy impact compaction was for pavements only.
Black Geotechnical and Landpac have successfully completed a number of projects where development has proceeded on uncontrolled fill over loose natural sand where the high energy impact compaction has improved the fill and the underlying sand. Some of these projects are listed below.
- Toyota Motor Corporation Head Office. Port Melbourne. Four storey office on high level strip and pad footings, on 2m of sand fill over loose sand with weak 'Coode Island Silt' at about 6m.
- Four hectare office development in Port Melbourne on 2m of sand fill over loose sand.
- In-situ compaction of loose sand up to 7m deep for the Jupiter's Convention Centre.
- 1.9 hectare site at Nelly Bay, Magnetic Island, on 2-7m of sand/clayey sand fill developed with twelve 3-4 level buildings on high level strip footings for the Blue-on-Blue resort.
- 1.75 hectare site at Palm Cove to be developed on interbedded loose to dense sands and soft to stiff clays as four level plus basement hotel and apartments on high level slab footings.